Assembly for a drug delivery device and drug delivery device

ABSTRACT

An assembly for a drug delivery device comprises a housing having a proximal end and a distal end, a dose button configured to be moved with respect to the housing for setting and delivering a dose of a drug, and a resilient setting member. For a dose delivery movement, the dose button is arranged to be moveable in the distal direction with respect to the housing from a dose delivery position, thereby deforming the resilient setting member to store energy in the resilient setting member. The assembly is configured to use the energy stored in the resilient setting member for a dose setting movement to move the dose button in the proximal direction with respect to the housing into the dose delivery position. Furthermore, a drug delivery device is provided.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to European Patent ApplicationNo. 10193754.8 filed Dec. 6, 2010, the entire contents of which areincorporated herein by reference.

FIELD OF INVENTION

This disclosure relates to an assembly for a drug delivery device. Thedisclosure further relates to a drug delivery device comprising theassembly.

BACKGROUND

In a drug delivery device, often, a bung within a cartridge containing aplurality of doses of a drug is displaced by a piston rod. Thereby, adose of the drug is expelled from the cartridge.

A drug delivery device is described in document EP 1 923 083 A1, forexample.

It is an object of the present disclosure to provide an assemblyfacilitating provision of an improved drug delivery device, for examplea device with increased safety and/or comfort for the user. Furthermore,an improved drug delivery device should be provided.

This object may be achieved by the subject matter of the independentclaims. Advantageous embodiments and refinements are subject matter ofthe dependent claims.

SUMMARY

One aspect relates to an assembly for a drug delivery device. Theassembly may comprise a housing. The housing may have a distal end. Thehousing may have a proximal end. The assembly may comprise a dosebutton. The dose button may be configured to be moved with respect tothe housing. In particular, the dose button may be moveable, preferablyin an axial direction with respect to the housing, for setting and/ordelivering a dose of a drug. The assembly may comprise a resilientsetting member. For a dose delivery movement, the dose button may bearranged to be moveable in the distal direction with respect to thehousing, preferably from a dose delivery position. Thereby, theresilient setting member may be deformed, e.g. compressed. The resilientsetting member may be deformed to store energy in the resilient settingmember. The assembly may be configured to use the energy stored in theresilient setting member for a dose setting movement to move the dosebutton in the proximal direction with respect to the housing, preferablyinto the dose delivery position.

The resilient setting member may be adapted to provide energy for anautomatic dose setting operation. In particular, the resilient settingmember may be adapted to automatically drive the dose button proximallyafter a dose delivery operation was performed by moving the dose buttondistally, thereby automatically preparing the device for a subsequentdose delivery operation. In this way, provision of a device with highcomfort for the user may be facilitated.

According to an embodiment, for the dose delivery movement, the dosebutton is moveable from the dose delivery position into a distal endposition with respect to the housing. In the distal end position, thedose button may be configured to mechanically cooperate with a proximalface of the housing such that further movement of the dose button in thedistal direction with respect to the housing may be prevented.

Mechanical cooperation of the dose button and the proximal face of thehousing may provide a distal end stop for the dose button. Distalmovement of the dose button beyond the distal end position, which couldlead to delivery of an overdose, may be prevented in this way.Accordingly, provision of a drug delivery device having high user safetymay be facilitated.

According to an embodiment, the housing comprises a bearing member. Thebearing member may be provided on an inner surface of the housing. Theresilient setting member may be arranged between the bearing member anda distal face of the dose button.

According to an embodiment, the resilient setting member is a spring,for example a compression spring.

According to an embodiment, the assembly comprises a drive mechanism.The drive mechanism may comprise a drive member. The drive member may bemoveable in the proximal direction with respect to the housing whensetting the dose of the drug. The drive member may be moveable in thedistal direction with respect to the housing when dispensing the setdose. Movement of the dose button may be transferred to the drive memberby mechanical cooperation of the dose button and the drive member.

The drive member may be adapted to operate through/within the housing.The drive member may be designed to translate axial, in particulardistal, movement through/within the drug delivery device.

The drive member may be permanently engaged with the dose button. Thedrive member may comprise engaging means. The dose button may comprisemating engaging means. The dose button may be prevented from movementwith respect to the drive member by mechanical cooperation of theengaging means and the mating engaging means.

According to an embodiment, the assembly comprises a piston rod. Thepiston rod may be adapted to operate through the housing. The piston rodmay be adapted to transfer a force in the distal direction from the dosebutton. Movement of the dose button in the distal direction with respectto the housing may be converted into movement of the piston rod in thedistal direction by means of mechanical interaction of the drive memberand the piston rod for dispensing the dose.

The drive member may be permanently or releasably engaged with thepiston rod. The piston rod may be adapted and arranged to translateaxial, in particular distal, movement through/within the drug deliverydevice, preferably from the drive member to a bung of the device, forthe purpose of dispensing a dose of the drug.

A further aspect relates to a drug delivery device. The drug deliverydevice may comprise the previously described assembly. The device maycomprise a cartridge. The cartridge may hold a drug, preferably aplurality of doses of the drug.

The device may be a re-usable device. Alternatively, the device may be adisposable device. The previously described assembly may provide anautomatic dose setting operation of the device. In this way, provisionof a user friendly drug delivery device may be facilitated.

According to an embodiment, the dose button is in the dose deliveryposition when the device is supplied from the manufacturer. Theresilient setting member may be in a relaxed state when the device issupplied from the manufacturer.

When supplied from the manufacturer, the device may be in a conditionready to dispense a dose of the drug from the cartridge. User-operatedsteps for making the device ready for operation may be redundant. Thismay help to increase the comfort for the user.

According to an embodiment, the drug delivery device comprises ablocking member. When the dose button is in the dose delivery position,the blocking member may be adapted and arranged to block movement of thedose button in the distal direction with respect to the housing fordispensing the dose.

In this way, an unintentional dose delivery operation may be prevented.User safety may be increased in this way.

According to an embodiment, the blocking member is externallyactuatable. When the blocking member is actuated, movement of the dosebutton in the distal direction for delivering the dose may be allowed.

In particular, the blocking member may be actuatable by the user todecouple the blocking member and the housing. Accordingly, uponactivation of the blocking member, the user can start a dose deliveryoperation. In this way, provision of a user-friendly device isfacilitated.

According to an embodiment, the blocking member is moveable with respectto the housing for decoupling the blocking member and the housing suchthat the dose button is moveable in the distal direction for deliveringthe dose.

When the blocking member and the housing are coupled, the dose buttonmay be positioned in the dose delivery position. The blocking member maybe operable to decouple, in particular to disengage, from the housing.When the blocking member and the housing are decoupled, a dose deliveryoperation may be allowed. In particular the dose button may then bemoveable from the dose delivery position in the distal direction withrespect to the housing.

The blocking member may be moveable in the radial direction with respectto the housing. The blocking member may be moved, preferably by a user,in the radial inward direction with respect to the housing fordecoupling the blocking member and the housing, thus enabling movementof the dose button in the distal direction for delivering the dose. Theblocking member may be moveable, preferably automatically moveable, inthe radial outward direction for coupling the blocking member and thehousing.

According to an embodiment, the blocking member is a resilient member.Alternatively, the blocking member may be a resiliently mounted member.The resilient member or the resiliently mounted member may be configuredsuch that a resilient force provided by the resilient member or theresiliently mounted member may move the blocking member in the radialoutward direction with respect to the housing for coupling the blockingmember to the housing when the dose button is moved in the proximaldirection for setting the dose.

At the end of the dose setting operation, the blocking member may beautomatically moveable in the radial outward direction. In particular,when the dose button was moved back into the dose delivery position, theblocking member may be automatically moved radially outwardly to couplewith the housing due to the energy stored in the blocking member.Accordingly, a subsequent dose delivery operation may be preventedautomatically until a further actuation of the blocking member takesplace to decouple the blocking member and the housing. Unintentionaldose delivery may be prevented in this way. This may help to increaseuser safety.

According to an embodiment, the blocking member is decoupled from thehousing when the dose button is out of the dose delivery position.

The blocking member may be operable to couple with the housing afterdose setting was completed, in particular when the dose button ispositioned in the dose delivery position. The dose button may beprevented from being moveable radially outwardly during the dose settingand/or the dose delivery operation, i.e. when the dose button is out ofthe dose delivery position. Unintentional coupling of the blockingmember and the housing and, thus, interruption of a dose setting and/orthe dose delivery operation may be prevented in this way.

According to an embodiment, the blocking member is connected to or isintegrated in the dose button.

The blocking member and the dose button may be formed unitarily.Manufacturing costs may be reduced in this way.

According to an embodiment, the housing comprises an engagement means.The engagement means may be adapted and arranged to mechanicallycooperate with the blocking member when the dose button is in the dosedelivery position. The engagement means may comprise an opening in thehousing. The opening may be configured to receive the blocking member.

In particular, the blocking member may engage the opening when the dosebutton is in the dose delivery position. Due to mechanical cooperationof the blocking member and the opening, the dose button may be preventedfrom movement with respect to the housing.

According to a preferred embodiment, an assembly for a drug deliverydevice is provided, the assembly comprising a housing having a proximalend and a distal end,

a dose button configured to be moved with respect to the housing forsetting and delivering a dose of a drug, and a resilient setting member.For a dose delivery movement, the dose button is arranged to be moveablein the distal direction with respect to the housing from a dose deliveryposition, thereby deforming the resilient setting member to store energyin the resilient setting member. The assembly is configured to use theenergy stored in the resilient setting member for a dose settingmovement to move the dose button in the proximal direction with respectto the housing into the dose delivery position.

The resilient setting member may provide energy for an automatic dosesetting operation. In this way, provision of a device with high usercomfort may be facilitated.

Of course, features described above in connection with different aspectsand embodiments may be combined with each other and with featuresdescribed below.

Further features, advantages and refinements become apparent from thefollowing description of the exemplary embodiments in connection withthe accompanying figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 schematically shows a perspective side view of a drug deliverydevice,

FIG. 2 schematically shows an exploded view of the drug delivery deviceof FIG. 1,

FIG. 3A schematically shows a perspective side view of the drug deliverydevice of FIG. 1 before a dose delivery operation takes place,

FIG. 3B schematically shows a sectional side view of the drug deliverydevice of FIG. 3A,

FIG. 4 schematically shows a sectional side view of the drug deliverydevice of FIG. 1 before a dose setting operation takes place,

FIG. 5A schematically shows a perspective side view of a dose button,

FIG. 5B schematically shows a sectional side view of the dose button ofFIG. 5A,

FIG. 6A schematically shows a perspective side view of a housing,

FIG. 6B schematically shows a sectional side view of the housing of FIG.6A,

FIG. 7A schematically shows a perspective side view of a drivemechanism,

FIG. 7B schematically shows a further perspective side view of the drivemechanism of FIG. 7A.

DETAILED DESCRIPTION

Like elements, elements of the same kind and identically acting elementsmay be provided with the same reference numerals in the figures.

In FIGS. 1 and 2 a drug delivery device 1 is shown. The drug deliverydevice 1 comprises a housing 2. The drug delivery device 1 and thehousing 2 have a distal end and a proximal end. The distal end isindicated by arrow 5. The proximal end is indicated by arrow 6. The term“distal end” designates that end of the drug delivery device 1 or acomponent thereof which is or is to be arranged closest to a dispensingend of the drug delivery device 1. The term “proximal end” designatesthat end of the device 1 or a component thereof which is or is to bearranged furthest away from the dispensing end of the device 1. Thedistal end and the proximal end are spaced apart from one another in thedirection of an axis (not explicitly shown). The axis may be the mainlongitudinal axis of the device 1.

The drug delivery device 1 comprises a cartridge 15. The cartridge 15 ispermanently or releasably retained within a cartridge holder 14. Thecartridge holder 14 stabilizes the cartridge 15 mechanically. Thecartridge holder 14 may be, permanently or releasably, attached to thehousing 2 of the drug delivery device 1. Alternatively, the cartridge 15may be permanently or releasably fixed to the housing 2. In this case,the cartridge holder 14 may be redundant.

The cartridge 15 contains a drug 16, preferably a plurality of doses ofthe drug 16. The drug 16 may be a fluid drug. The term “drug”, as usedherein, preferably means a pharmaceutical formulation containing atleast one pharmaceutically active compound,

wherein in one embodiment the pharmaceutically active compound has amolecular weight up to 1500 Da and/or is a peptide, a proteine, apolysaccharide, a vaccine, a DNA, a RNA, an enzyme, an antibody, ahormone or an oligonucleotide, or a mixture of the above-mentionedpharmaceutically active compound,

wherein in a further embodiment the pharmaceutically active compound isuseful for the treatment and/or prophylaxis of diabetes mellitus orcomplications associated with diabetes mellitus such as diabeticretinopathy, thromboembolism disorders such as deep vein or pulmonarythromboembolism, acute coronary syndrome (ACS), angina, myocardialinfarction, cancer, macular degeneration, inflammation, hay fever,atherosclerosis and/or rheumatoid arthritis,

wherein in a further embodiment the pharmaceutically active compoundcomprises at least one peptide for the treatment and/or prophylaxis ofdiabetes mellitus or complications associated with diabetes mellitussuch as diabetic retinopathy,

wherein in a further embodiment the pharmaceutically active compoundcomprises at least one human insulin or a human insulin analogue orderivative, glucagon-like peptide (GLP-1) or an analogue or derivativethereof, or exedin-3 or exedin-4 or an analogue or derivative ofexedin-3 or exedin-4.

Insulin analogues are for example Gly(A21), Arg(B31), Arg(B32) humaninsulin; Lys(B3), Glu(B29) human insulin; Lys(B28), Pro(B29) humaninsulin; Asp(B28) human insulin; human insulin, wherein proline inposition B28 is replaced by Asp, Lys, Leu, Val or Ala and wherein inposition B29 Lys may be replaced by Pro; Ala(B26) human insulin;Des(B28-B30) human insulin; Des(B27) human insulin and Des(B30) humaninsulin.

Insulin derivates are for example B29-N-myristoyl-des(B30) humaninsulin; B29-N-palmitoyl-des(B 30) human insulin; B29-N-myristoyl humaninsulin; B29-N-palmitoyl human insulin; B28-N-myristoyl LysB28ProB29human insulin; B28-N-palmitoyl-LysB28ProB29 human insulin;B30-N-myristoyl-ThrB29LysB30 human insulin; B30-N-palmitoyl-ThrB29LysB30human insulin; B29-N—(N-palmitoyl-Y-glutamyl)-des(B30) human insulin;B29-N—(N-lithocholyl-Y-glutamyl)-des(B30) human insulin;B29-N-(w-carboxyheptadecanoyl)-des(B30) human insulin andB29-N-(ω-carboxyheptadecanoyl) human insulin.

Exendin-4 for example means Exendin-4(1-39), a peptide of the sequenceH-His-Gly-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-Lys-Gln-Met-Glu-Glu-Glu-Ala-Val-Arg-Leu-Phe-Ile-Glu-Trp-Leu-Lys-Asn-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

Exendin-4 derivatives are for example selected from the following listof compounds:

-   H-(Lys)4-des Pro36, des Pro37 Exendin-4(1-39)-NH2,-   H-(Lys)5-des Pro36, des Pro37 Exendin-4(1-39)-NH2,-   des Pro36 [Asp28] Exendin-4(1-39),-   des Pro36 [IsoAsp28] Exendin-4(1-39),-   des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),-   des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),-   des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),-   des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),-   des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),-   des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39); or-   des Pro36 [Asp28] Exendin-4(1-39),-   des Pro36 [IsoAsp28] Exendin-4(1-39),-   des Pro36 [Met(O)14, Asp28] Exendin-4(1-39),-   des Pro36 [Met(O)14, IsoAsp28] Exendin-4(1-39),-   des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39),-   des Pro36 [Trp(O2)25, IsoAsp28] Exendin-4(1-39),-   des Pro36 [Met(O)14 Trp(O2)25, Asp28] Exendin-4(1-39),-   des Pro36 [Met(O)14 Trp(O2)25, IsoAsp28] Exendin-4(1-39),    wherein the group -Lys6-NH2 may be bound to the C-terminus of the    Exendin-4 derivative;    or an Exendin-4 derivative of the sequence-   H-(Lys)6-des Pro36 [Asp28] Exendin-4(1-39)-Lys6-NH2,-   des Asp28 Pro36, Pro37, Pro38Exendin-4(1-39)-NH2,-   H-(Lys)6-des Pro36, Pro38 [Asp28] Exendin-4(1-39)-NH2,-   H-Asn-(Glu)5des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-NH2,-   des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,-   H-(Lys)6-des Pro36, Pro37, Pro38 [Asp28] Exendin-4(1-39)-(Lys)6-NH2,-   H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Asp28]    Exendin-4(1-39)-(Lys)6-NH2,-   H-(Lys)6-des Pro36 [Trp(O2)25, Asp28] Exendin-4(1-39)-Lys6-NH2,-   H-des Asp28 Pro36, Pro37, Pro38 [Trp(O2)25] Exendin-4(1-39)-NH2,-   H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]    Exendin-4(1-39)-NH2,-   H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]    Exendin-4(1-39)-NH2,-   des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]    Exendin-4(1-39)-(Lys)6-NH2,-   H-(Lys)6-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]    Exendin-4(1-39)-(Lys)6-NH2,-   H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Trp(O2)25, Asp28]    Exendin-4(1-39)-(Lys)6-NH2,-   H-(Lys)6-des Pro36 [Met(O)14, Asp28] Exendin-4(1-39)-Lys6-NH2,-   des Met(O)14 Asp28 Pro36, Pro37, Pro38 Exendin-4(1-39)-NH2,-   H-(Lys)6-desPro36, Pro37, Pro38 [Met(O)14, Asp28]    Exendin-4(1-39)-NH2,-   H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]    Exendin-4(1-39)-NH2,-   des Pro36, Pro37, Pro38 [Met(O)14, Asp28]    Exendin-4(1-39)-(Lys)6-NH2,-   H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]    Exendin-4(1-39)-(Lys)6-NH2,-   H-Asn-(Glu)5 des Pro36, Pro37, Pro38 [Met(O)14, Asp28]    Exendin-4(1-39)-(Lys)6-NH2,-   H-Lys6-des Pro36 [Met(O)14, Trp(O2)25, Asp28]    Exendin-4(1-39)-Lys6-NH2,-   H-des Asp28 Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25]    Exendin-4(1-39)-NH2,-   H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Asp28]    Exendin-4(1-39)-NH2,-   H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]    Exendin-4(1-39)-NH2,-   des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]    Exendin-4(1-39)-(Lys)6-NH2,-   H-(Lys)6-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]    Exendin-4(S1-39)-(Lys)6-NH2,-   H-Asn-(Glu)5-des Pro36, Pro37, Pro38 [Met(O)14, Trp(O2)25, Asp28]    Exendin-4(1-39)-(Lys)6-NH2;    or a pharmaceutically acceptable salt or solvate of any one of the    afore-mentioned Exedin-4 derivative.

Hormones are for example hypophysis hormones or hypothalamus hormones orregulatory active peptides and their antagonists as listed in RoteListe, ed. 2008, Chapter 50, such as Gonadotropine (Follitropin,Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin),Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin,Buserelin, Nafarelin, Goserelin.

A polysaccharide is for example a glucosaminoglycane, a hyaluronic acid,a heparin, a low molecular weight heparin or an ultra low molecularweight heparin or a derivative thereof, or a sulphated, e.g. apoly-sulphated form of the above-mentioned polysaccharides, and/or apharmaceutically acceptable salt thereof. An example of apharmaceutically acceptable salt of a poly-sulphated low molecularweight heparin is enoxaparin sodium.

Pharmaceutically acceptable salts are for example acid addition saltsand basic salts. Acid addition salts are e.g. HCl or HBr salts. Basicsalts are e.g. salts having a cation selected from alkali or alkaline,e.g. Na+, or K+, or Ca2+, or an ammonium ion N+(R1)(R2)(R3)(R4), whereinR1 to R4 independently of each other mean: hydrogen, an optionallysubstituted C1-C6-alkyl group, an optionally substituted C2-C6-alkenylgroup, an optionally substituted C6-C10-aryl group, or an optionallysubstituted C6-C10-heteroaryl group. Further examples ofpharmaceutically acceptable salts are described in “Remington'sPharmaceutical Sciences” 17. ed. Alfonso R. Gennaro (Ed.), MarkPublishing Company, Easton, Pa., U.S.A., 1985 and in Encyclopedia ofPharmaceutical Technology.

Pharmaceutically acceptable solvates are for example hydrates.

The cartridge 15 has an outlet 18. The outlet 18 is covered by amembrane 21. For delivery of the drug 16, the membrane 21 may bepenetrated, for example pierced, e.g. by a needle assembly (notexplicitly shown). A bung 17 is slideably retained within the cartridge15. The bung 17 seals the cartridge 15 proximally. Movement of the bung17 in the distal direction with respect to the cartridge 15 causes thedrug 16 to be dispensed from the cartridge 15 through the outlet 18.

The device 1 comprises a dose button 4. The dose button 4 is moveable inthe proximal direction, preferably from a distal end position into adose delivery position, for setting a dose of the drug 16. The dosebutton 4 is moveable in the distal direction, preferably from the dosedelivery position into the distal end position, for dispensing the setdose. In FIG. 1 the dose button 4 is positioned in the distal endposition. The dose button 4 may comprise or may be embodied as a sleeve.

The dose button 4 comprises an interaction face 22 (see also FIGS. 5Aand 5B). The interaction face 22 is arranged in the proximal section ofthe dose button 4. The interaction face 22 may be formed by a flangeextending circumferentially around an outer surface of the dose button4, for example. Mechanical cooperation of the interaction face 22 and aproximal face 23 of the housing 2 (see also FIGS. 6A and 6B) may preventfurther movement of the dose button 4 in the distal direction when thedose button 4 is in the distal end position. Accordingly, theinteraction face 22 of the dose button 4 may provide a distal end stopfor the dose button 4.

The device comprises a drive mechanism 24 (see FIGS. 7A and 7B). Thedrive mechanism 24 comprises a drive member 12. The drive member 12 andthe dose button 4 are secured to each other to prevent rotational and/oraxial movement between one another. The drive member 12 comprisesengaging means 25 (see FIGS. 7A and 7B). Engaging means 25 may comprisea rib, preferably a plurality of ribs. The dose button 4 comprisesmating engaging means 26 (see FIGS. 5A and 5B). Engaging means 25 maycomprise a nut, preferably a plurality of nuts. Movement of the dosebutton 4 is converted into movement of the drive member 12 with respectto the housing 2 by mechanical cooperation of the engaging means 25 andthe mating engaging means 26. The drive member 12 transfers movement ofthe dose button 4 into movement of a piston rod 13 for dispensing thedose by mechanical cooperation of the drive member 12 and the piston rod13. The drive member 12 extends about the piston rod 13 (see FIGS. 7Aand 7B).

The piston rod 13 is designed to operate through the housing 2 of thedrug delivery device 1. The piston rod 13 is designed to transfer axialmovement through the drug delivery device 1 for the purpose ofdelivering the drug 16. The piston rod 13 is configured to be axiallydisplaced in the distal direction for delivering the dose. Preferably,the piston rod 13 is prevented from being axially displaced in theproximal direction when setting a dose of the drug 4 by mechanicalcooperation with a fixed part of the drive mechanism 24. A bearingsurface 13A located at the distal end of the piston rod 13 is disposedto abut the proximal face of the bung 17.

The fixed part of the drive mechanism 24 comprises a locking member 27(see FIG. 7B). A mating locking member 28 (see FIG. 6B) may be providedon the inner surface 11 of the housing 2. Movement of the fixed partwith respect to the housing 2 may be prevented by mechanical cooperationof locking member 27 and mating locking member 28. The fixed partmechanically cooperates with the drive member 12, e.g. by providingteeth for mechanical interaction with a gear wheel of the drive member12. More details concerning the drive mechanism 24 can be taken fromdocument WO 08058666 A1 the disclosure of which is incorporated hereinby reference.

The device 1 comprises a cap 19. The cap 19 is configured to cover thedistal end of the device 1. The cap 19 comprises a window aperture 20. Adosing scale provided on the cartridge holder 14 and/or the cartridge 15may be visible through the window aperture 20.

The device 1 comprises a resilient setting member 7. The resilientsetting member 7 may be spring, e.g. a compression spring. The resilientsetting member 7 exerts a force, in particular a proximally directedforce, onto the dose button 4. An energy stored in the resilient settingmember 7 during a dose delivery operation may be used for driving thedose button 4 proximally for automatically setting a dose of the drug16, which is explained later on in more detail. The resilient settingmember 7 is provided between a distal face 8 of the dose button 4 and abearing member 9. The bearing member 9 is provided on an inner surface11 of the housing 2 (see, in particular FIG. 5A, 5B and FIG. 6A, 6B).The bearing member 8 may be a protrusion or a flange providedcircumferentially on the inner surface 11 of the housing 2.

The device 1 may comprise a blocking member 3. The blocking member 3 isconfigured to mechanically interact with the housing 2. The blockingmember 3 is adapted and arranged to be releasably coupled to the housing2. The housing 2 comprises an engagement means 10, e.g. an opening. Saidengagement means 10 is configured to receive the blocking member 3 forcoupling the blocking member 3 and the housing 2. Thus, an interlock ofthe engagement means 10 and the blocking member 3 is formed. Theblocking member 3 and the housing 2 are coupled to one another when thedose button 4 is in the dose delivery position.

When the blocking member 3 is coupled to the housing 2, movement of thedose button 4 with respect to the housing 2, in particular distalmovement for delivering the set dose, is prevented. When the blockingmember 3 and the housing 2 are decoupled, a dose delivery movement ofthe dose button 4 with respect to the housing 2 in the distal directionis allowed. Furthermore, when the blocking member 3 and the housing 2are decoupled, a dose setting movement of the dose button 4 with respectto the housing 2 in the proximal direction driven by the energy storedin the resilient setting member 7 is allowed. Operation of setting anddelivering a dose and, in particular, operation of the blocking member 3is described in the following text in detail.

The blocking member 3 is connected to or is integrated in the dosebutton 4. The blocking member 3 is externally actuatable, in particularuser actuatable. The blocking member 3 is moveable with respect to thehousing 2 for coupling and/or decoupling the blocking member 3 and thehousing 2. In particular, the blocking member 3 is moveable in theradial direction with respect to the housing 2. The blocking member 3 ismoveable in the radial inward direction with respect to the housing 2,preferably by the user, for decoupling the blocking member 3 and thehousing 2. The blocking member 3 is moveable in the radial outwarddirection with respect to the housing 2 for coupling the blocking member3 and the housing 2, thus preventing movement of the dose button 4 withrespect to the housing 2.

The blocking member 3 comprises a resilient member or a resilientlymounted member. A resilient force provided by the resilient member orthe resiliently mounted member automatically moves the blocking member 3in the radial outward direction with respect to the housing 2 forcoupling the blocking member 3 to the housing 2 when the dose button 4is in the dose delivery position, which is explained later on in moredetail. The blocking member 3 comprises a knob 29. The knob 29 isconnected to the dose button 4 by means of a flexible web 30 (see FIG.5A). When the dose button 4 is in the dose delivery position, the knob29 protrudes from the outer surface of the housing 2. Accordingly, theblocking member 3 is accessible from the outside of the device 1 whenthe dose button 4 is in the dose delivery position.

FIG. 3A schematically shows a perspective side view of the drug deliverydevice of FIG. 1 before a dose delivery operation takes place.

FIG. 3B schematically shows a sectional side view of the drug deliverydevice of FIG. 3A.

FIG. 4 schematically shows a sectional side view of the drug deliverydevice of FIG. 1 after the dose delivery operation took place and beforea dose setting operation takes place.

In an initial state of the device 1, e.g. the state of the device 1 whenthe device 1 is supplied to the user by the manufacturer, the dosebutton 4 is positioned in the dose delivery position as shown in FIGS.3A and 3B. The housing 2 and the blocking member 3 are coupled to oneanother due to mechanical cooperation of the blocking member 3 and theengagement means 10 (not explicitly shown in FIGS. 3A and 3B). Thus,movement of the dose button 4 with respect to the housing 2 fordelivering the dose is prevented. The resilient setting member 7 is in acompletely or partly relaxed state.

For initiating a dose delivery operation, the user moves the blockingmember 3 radially inwardly with respect to the housing 2. Thereby, theblocking member 3 decouples from the housing 2, in particular from theengagement means 10. When the blocking member 3 is moved radiallyinwardly, an energy is stored in the blocking member 3. In particular,when the blocking member 3 was moved radially inwardly, the blockingmember 3 provides a resilient force. The force is directed radiallyoutwardly with respect to the housing 2. When the dose button 4 is outof the dose delivery position, the blocking member 3 is prevented frommoving radially outwardly driven by the energy stored in the blockingmember 3 due to mechanical cooperation of the blocking member 3 and theinner surface 11 of the housing 2. When the dose button 4 is out of thedose delivery position, the blocking member 3 may be guided along aguide track arranged on the inner surface 11 of the housing 2 (notexplicitly shown).

When the blocking member 3 and the housing 2 are decoupled, the dosebutton 4 is moveable with respect to the housing 2. For delivering theset dose, the user now pushes onto the dose button 4, thereby moving thedose button 4 distally. Thereby, the resilient setting member 7 iselastically deformed, e.g. compressed. This stores energy in theresilient setting member 7. In particular, the user moves the dosebutton 4 distally against the proximally directed force provided by theresilient setting member 7. The dose button 4 is moved distally untilthe interaction face 22 of the dose button 4 abuts the proximal face 23of the housing 2. When the interaction face 22 of the dose button 4abuts the proximal face 23 of the housing 2, the dose button 4 is in thedistal end position and the set dose of the drug 16 was dispensedcompletely from the device 1.

After dose delivery was completed, the user releases the dose button 4.Accordingly, the resilient setting member 7 is allowed to relax as thereis no longer a distally directed force provided by the usercounteracting the proximally directed force provided by the resilientsetting member 7. When the resilient setting member 7 relaxes, theresilient setting member automatically moves the dose button 4proximally out of the distal end position and back into the dosedelivery position (see FIG. 4), thereby setting a subsequent dose of thedrug 16. A proximal end stop (not explicitly shown) may be provided inthe housing 2, e.g. in a proximal section of the housing 2, to preventmovement of the dose button 4 in the proximal direction beyond the dosedelivery position by mechanical cooperation of the proximal end stop andthe dose button 4.

When the device is in the dose delivery position, the blocking member 3and the engagement means 10 overlap. Accordingly, due to the resilientenergy stored in the blocking member 3, the blocking member 3 isautomatically moved radially outwardly such that the blocking member 3mechanically cooperates with the engagement means 10 and such that thedose button 4 is prevented from distal movement with respect to thehousing 2 until the user actuates again the blocking member 3 fordelivering a subsequent dose of the drug 16.

The drug delivery device 1 may be a pen-type device, in particular apen-type injector. The device 1 may be a disposable or a re-usabledevice. The device 1 may be especially suitable for dispensing fixeddoses of the drug 16, e.g. doses the size of which may not be varied bythe user. Accordingly, the dose button 4 may be moved by the samedistance in the proximal direction with respect to the housing 2 duringeach dose setting operation.

The invention claimed is:
 1. An assembly for a drug delivery device,comprising a housing having a proximal end and a distal end, a dosebutton configured to be moved with respect to the housing for settingand delivering a dose of a drug, and a resilient setting member,wherein, for a dose delivery movement, the dose button is arranged to bemoveable in the distal direction with respect to the housing from a dosedelivery position, thereby deforming the resilient setting member tostore energy in the resilient setting member, and wherein the assemblyis configured to use the energy stored in the resilient setting memberfor a dose setting movement to move the dose button in the proximaldirection with respect to the housing into the dose delivery position.2. The assembly of claim 1, wherein, for the dose delivery movement, thedose button is moveable from the dose delivery position into a distalend position with respect to the housing, and wherein, in the distal endposition, the dose button is configured to mechanically cooperate with aproximal face of the housing such that further movement of the dosebutton in the distal direction with respect to the housing is prevented.3. The assembly of claim 1, wherein the housing comprises a bearingmember provided on an inner surface of the housing, and wherein theresilient setting member is arranged between the bearing member and adistal face of the dose button.
 4. The assembly according to claim 1,wherein the resilient setting member is a spring.
 5. The assemblyaccording to claim 1, comprising a drive mechanism, the drive mechanismcomprising a drive member, wherein the drive member is moveable in theproximal direction with respect to the housing when setting the dose ofthe drug and moveable in the distal direction with respect to thehousing when dispensing the set dose, wherein movement of the dosebutton is transferred to the drive member by mechanical cooperation ofthe dose button and the drive member.
 6. The assembly of claim 5,wherein the drive member comprises an engaging component and the dosebutton comprises a mating engaging component, and wherein the dosebutton is prevented from movement with respect to the drive member bymechanical cooperation of the engaging and the mating engagingcomponents.
 7. The assembly according to claim 5, comprising a pistonrod adapted to operate through the housing and to transfer a force inthe distal direction from the dose button, wherein movement of the dosebutton in the distal direction with respect to the housing is convertedinto movement of the piston rod in the distal direction by means ofmechanical interaction of the drive member and the piston rod fordispensing the dose.
 8. A drug delivery device comprising the assemblyaccording to claim 1, wherein the device comprises a cartridge holding adrug.
 9. The drug delivery device of claim 8, wherein the dose button isin the dose delivery position when the device is supplied from themanufacturer.
 10. The drug delivery device of claim 8, wherein theresilient setting member is in a relaxed state when the device issupplied from the manufacturer.
 11. The drug delivery device of claim 9,comprising a blocking member, wherein, when the dose button is in thedose delivery position, the blocking member is adapted and arranged toblock movement of the dose button in the distal direction with respectto the housing for dispensing the dose.
 12. The drug delivery device ofclaim 11, wherein the blocking member is externally actuatable, wherein,when the blocking member is actuated, movement of the dose button in thedistal direction for delivering the dose is allowed.
 13. The drugdelivery device of claim 11, wherein the blocking member is moveablewith respect to the housing for decoupling the blocking member and thehousing such that the dose button is moveable in the distal directionfor delivering the dose.